The Frame around a Graphics part like ArrayPlot is not always complete. The Right and/of Bottom part are missing depending on the Image Size.
Is there some explanation for this behavior? Can this be prevented?
With Mathematica 13.2 on Macintosh the frame becomes fully visible when I reevaluate your inputs.
I am able to reproduce the issue by WL 13.2 on Windows 10 Home.
It may be a problem with screen resolution. What happens if you change the magnification of the notebook?
Stephen Wolfram brought up this issue and others on a recent Live CEOing stream.
I tried to change the Notebook magnification. Problem persist.
The Frame comes and go’s when I zoom the Graphics window (click and drag corner of orange rectangle)
As far as I can tell, the issue first appeared in version 13.0.1 on my Windows 10 (64-bity) OS. I reported it to Wolfram Tech Support in April last year.
For version 13.0.1 the issue persisted in a bitmap export (jpg, png) of a plot, but not in a vector graphic export of the plot e.g. pdf or svg.
The edges of axes disappear if you select another plot, change notebook magnification or when you resize a plot, or when you create multiple plots in one (some plots have no axes on the edges).